基于表面等离子体共振的光子晶体光纤折射率传感器的设计与分析

为了实现光子晶体光纤在近红外波段下的高灵敏度传感,设计了一种基于表面等离子体共振的光子晶体光纤(SPR-PCF)折射率型传感器。光纤内部的空气孔呈六边形排列,金纳米层完全包覆光纤外璧并与圆形待测物通道接触。利用有限元矢量软件COMSOL对SPR-PCF传感器的光学特性进行数值模拟仿真,得到不同待测物折射率的共振波长并绘制出纤芯损耗光谱,通过纤芯损耗光谱来对SPR-PCF传感器的传感特性进行分析。实验结果表明,其折射率测量区间为1.31~1.38,最大光谱灵敏度为104 nm/RIU,最大振幅灵敏度为200RIU-1,折射率测量精度为2.94×10-5RIU。     

基于SPR效应的金-PDMS涂覆光子晶体光纤高灵敏度温度测量

通过在光子晶体光纤(PCF)包层外侧填镀金纳米膜及PDMS温敏薄膜,设计了一种基于表面等离子体共振(SPR)效应的高灵敏度温度传感器,具有结构简单、工艺成熟、可逆性好的优点。PDMS的有效折射率会随温度的增加而减小,从而引起纤芯模式的损耗峰向短波方向移动。在完全匹配层边界条件下,利用全矢量有限元法分析SPR-PCF的损耗谱特性,实现了温度的高灵敏度精确快速测量。在22~47℃的温度范围内,所提传感器的温度灵敏度可达到-8.18 nm/℃,这种传感测量方法能拓展应用于各类安全检测和智能监测领域。     

基于双芯光子晶体光纤的高灵敏度椭圆侧芯表面等离子体共振折射率传感特性北大核心CSCD

提出了一种基于双芯光子晶体光纤(PCF)的高灵敏度椭圆侧芯表面等离子体共振(SPR)折射率传感模型。在各向异性的完美匹配层边界条件下利用全矢量有限元法对传感器特性进行了数值仿真。研究发现:在椭圆侧芯中涂覆金属银纳米层可以实现SPR,共振峰对检测孔的折射率变化具有很高的传感灵敏度;与圆形结构相比,所提椭圆侧芯结构中的纤芯基模和金属表面等离子体激元(SPP)模式更易实现相位匹配;当椭圆率为0.7时,灵敏度在1.45~1.50的折射率范围内可达10412nm·RIU^(-1),且传感曲线线性度高;椭圆侧芯结构能够有效抑制高阶SPP模式,避免基模与多个SPP模式耦合形成干扰。     

基于表面等离子体共振的光子晶体光纤生物传感

为解决电化学生物传感的电磁干扰,提高光学生物传感的灵敏度,提出了一种基于表面等离子体共振(SPR)的光子晶体光纤(PCF)传感结构并将其应用于脱氧核糖核酸的检测中.为了易于检测,将Au膜镀在PCF的外表面直接接触待测溶液.利用全矢量有限元法结合各向异性的完美匹配层对该结构进行数值研究.结果 表明,在1.333～1.347折射率范围内,该结构具有明显的SPR效应,在1300～1400 nm波长范围内形成了不同位置的共振损耗峰.当Au膜厚度为60 nm、占空比为0.6、孔直径为1.2 μm时,该结构的灵敏度可达到7250 nm/RIU(RIU为折射率单元),检测限可达到10-6量级,品质因数为145 RIU-1.该结构在生物传感、液态物质检测等领域具有潜在的应用前景.     

基于液体填充的光子晶体光纤温度传感特性分析

提出了一种基于在折射率引导型光子晶体光纤(PCF)中填充高折射率温度系数液体的新型折射率型光纤温度传感器.通过建立理论模型,设定入射波长和材料参数及完美匹配层边界条件,采用全矢量有限元法对六角形结构排列的折射率引导型光子晶体光纤的温度特性进行了分析.研究表明,在空气孔中填充液体乙醇,PCF模场分布随着温度变化明显,其有效折射率和限制损耗都随着温度升高而减小.相同的孔间距,占空比越大,输入波长越长,有效折射率和限制损耗受温度影响越大.当波长为1500 nm,占空比为0.7,温度从-20℃升至70℃时,限制损耗从3.5×102dB/m减小到22 dB/m.     

光子晶体光纤液压传感技术研究进展

基于光子晶体光纤(PCF)的液压传感技术具有灵敏度高、抗干扰能力强、适应恶劣环境等优点,具有重要的研究意义和广泛的应用前景,因此受到研究人员的特别关注。在简要介绍PCF液压传感基本原理的基础上,重点回顾了几种典型的PCF液压传感技术,即双折射PCF液压传感技术、PCF光栅液压传感技术、法布里-珀罗(Fabry-P’erot)腔PCF液压传感技术、双芯PCF液压传感技术,分别介绍了这四种液压传感技术的原理与技术方案,并对各自的性能进行了分析、比较和总结。最后简要归纳了PCF液压传感技术的研究现状及未来发展趋势。     

直接熔融塌陷光子晶体光纤马赫-曾德尔干涉仪的折射率传感特性

研制了一种直接熔融塌陷锥形光子晶体光纤(PCF)马赫-曾德尔干涉仪(MZI)传感器,它是通过电弧放电的方法使光子晶体光纤空气孔受热塌陷,从而直接在光子晶体光纤上形成一个锥区制作而成的,可通过控制电弧参数以及放电次数来灵活控制锥区结构。研究了不同锥区长度下的输出光谱及其传输光谱随外界(RI)折射率的变化关系。实验结果表明,随着锥区长度的增加,在整个波长范围内MZI输出光谱的自由光谱区减小,且自由光谱区在1554.34nm波长附近由33.38nm减小到7.86nm。在1.3414~1.3862折射率变化范围内,该传感器的折射率测量灵敏度可达276.38nm/RIU(RIU为折射率单位)。     

选择性填充的光子晶体光纤传感特性研究

针对填充时利用不同填充结构材料对光子晶体光纤(photonic crystal fiber,FCF)传感特性的影响进行了研究,通过建立理论模型,利用有限元模拟对填充后的FCF的温度特性进行了分析。研究表明,填充折射率匹配液后,光纤传感器的温度灵敏度明显增大,对于相同的填充结构,填充占空比越大,输入波长越长,传感器的温度灵敏度越高。     

High-sensitivity photonic crystal fiber sensor based on surface plasmon resonance

In this paper, we propose a photonic crystal fiber (PCF) sensor based on the surface plasmonic resonance (SPR) effect for simultaneous temperature and refractive index (RI) measurement. The coupling characteristics and sensing performance of the sensor are analyzed using the full vector finite element method (FEM). The sensor provides two channels for independent measurement of RI and temperature. When operating independently, channel I supports y-polarized light with a sensitivity of up to 7 000 nm/RIU for detecting RI, while channel II supports x-polarized light with a sensitivity of up to 16 nm/°C for detecting temperature. Additionally, we investigate the influence of gold layer thickness on the sensing performance to optimize the sensor.     

A high sensitivity localized surface plasmon resonance sensor based on D-shaped photonic crystal fiber for low refractive index detection

In this paper, a localized surface plasmon resonance (LSPR) refractive index sensor based on photonic crystal fiber (PCF) is proposed to solve the problem of low refractive index analyte detection. 31 silver nanowires are placed on the surface of the D-shaped PCF, which increases the contact area between the plasma material and the analyte. The simulation results indicate that the maximum sensitivity of the sensor reaches 16 400 nm/RIU, and the refractive index detection range is 1.26—1.33. It is proved that the sensor has a good prospect in low refractive index detection.     

应用于折射率检测的光纤表面等离子体波传感器的研究

光纤表面等离子体波传感器具有结构简单、灵敏度高等特点,在机敏结构中具有非常重要的应用前景。运用光纤表面等离子体波来测量折射率是一种简便、灵敏的方法,我们可以利用这一特性制作出通过检测折射率对复合材料进行固化检测的光纤表面等离子体波传感器。本文介绍了光纤表面等离子体波传感器的基本原理及利用这种光纤传感器来测量折射率的初步研究。     

A surface plasmon resonance sensor based on a multi-core photonic crystal fiber

A surface plasmon resonance(SPR) sensor based on a multi-core photonic crystal fiber(PCF) is presented in this paper.There is only one analyte channel positioned in the center of the PCF cross section,rather than several closely arranged analyte channels around the central core.So the design of this sensor not only reduces the consumption of gold and samples,but also effectively avoids the interference between neighboring analyte channels.Optical field distributions of this fiber at different wavelengths and the sensing properties of this sensor are theoretically analyzed and discussed using finite element method(FEM).Simulation results confirm that both the thickness of metallic layer and the fiber structural parameters have significant effect on sensing performance.The amplitude sensitivity of the sensor is found to be 1.74×10-5RIU,and the spectral sensitivity is 3300 nm/RIU,corresponding to a resolution of 3.03×10-5 RIU.Finally,in order to achieve PCF-SPR sensing characteristics,an experiment design scheme based on spectroscopic detection method is proposed.     

D型环光子晶体光纤表面等离子体共振传感器

提出了一种中红外波段宽范围低折射率检测的D型环双芯光子晶体光纤表面等离子体共振传感器。该结构为一个D型环,并在其内外表面都沉积一层金属层。采用全矢量有限元方法分析了该传感器的性能。结果表明,该传感器可以在中红外波段实现低折射率传感,并具有高传感灵敏度特性。分析物的折射率可检测范围为120～138,平均波长灵敏度和最大波长灵敏度可分别达到13717nm/RIU和21150nm/RIU,分辨率可达到194×10-5 RIU。该传感器可在化学、生物以及环境检测等领域有重要的应用。     

表面等离子体共振类熊猫型光子晶体光纤传感器

分析了基于表面等离子体共振类熊猫型的光子晶体光纤传感器,采用基于全矢量有限元法（FEM）对光纤模式进行了数值计算,在各向异性完美匹配层（PML）边界条件下,求解模场的有效折射率。讨论了各个参量的尺寸对传感的影响。计算表明,激发的等离子体对环境介质折射率的变化非常敏感,所设计传感器最大光谱灵敏度达到2 μm/RIU,若光谱仪的分辨率为10 pm,则传感器的分辨率可以达到5×10-6 RIU。     

High-sensitivity refractive index sensors based on fused tapered photonic crystal fiber

In this paper, a novel liquid refractive index (RI) sensor based on fused tapered photonic crystal fiber (PCF) is proposed. It is fabricated by fusing and tapering a section of PCF which is spliced with two single-mode fibers (SMFs). Due to the fused biconical taper method, the sensor becomes longer and thinner, to make the change of the outside RI has more direct effects on the internal optical field of the PCF, which finally enhances the sensitivity of this sensor. Experimental results show that the transmission spectra of the sensor are red-shifted obviously with the increase of RI. The longer the tapered region of the sensor, the higher the sensitivity is. This sensor has the advantages of simple structure, easy fabrication, high performance and so on, so it has potential applications in RI measurement.     

Intermodal interference based refractive index sensor employing elliptical core photonic crystal fiber

A refractive index (RI) sensor based on elliptical core photonic crystal fiber (EC-PCF) has been proposed. The asymmetric elliptical core introduces the polarization-dependent characteristics of the fiber core modes. The performances of intermodal interference between the intrinsic polarization fiber core modes are investigated by contrast in two interferometers based on the Mach-Zehnder (M-Z) and Sagnac interference model. In addition, the RI sensing characteristics of the two interferometers are studied by successively filling the three layers air holes closest to the elliptical core in the cladding. The results show that the M-Z interference between LP01 and LP11 mode in the same polarized direction is featured with the incremental RI sensing sensitivity as the decreasing interference length, and the infilled scope around the elliptical core has a weak correlation with the RI sensing sensitivity. Due to the high birefringence of LP11 mode, the Sagnac interferometer has better RI sensing performance, the maximum RI sensing sensitivity of 12 000 nm/RIU is achieved under the innermost one layer air holes infilled with RI matching liquid of RI=1.39 at the pre-setting EC-PCF length of 12 cm, which is two orders of magnitude higher than the M-Z interferometer with the same fiber length. The series of theoretical optimized analysis would provide guidance for the applications in the field of biochemical sensing.     

基于表面等离子体共振的光子晶体光纤癌胚抗原浓度传感器

为了提高生物参量检测的灵敏度和避免电磁干扰,提出一种基于表面等离子共振的光子晶体光纤传感器应用于癌胚抗原(CEA)溶液的检测.该传感器采用不同直径空气孔进行三层排列的结构,将金薄膜作为金属层镀在纤芯表面,并在金薄膜和待测CEA溶液间增加一层基于核酸适配子的特异性适配层,采用全矢量有限元法对该传感器进行数值模拟与仿真.仿...     

基于多模态双偏置光纤的折射率传感机理研究

提出了一种基于双偏置结构光纤马赫-曾德干涉仪(Mach-Zehnder interferometer, MZI)的超高灵敏度折射率传感器,理论分析了偏置型MZI的干涉机理。通过光束传播法(beam propagation method, BPM)模拟分析了多模态偏置光纤的折射率传感特性、以及在不同偏置长度和折射率范围内折射率灵敏度的变化,对比了单偏置与双偏置的传感特性。仿真结果表明,在折射率为1.333 0—1.334 0的范围内,单偏置MZI的折射率灵敏度为-5 557 nm/RIU,而双偏置MZI的折射率灵敏度为-14 071 nm/RIU,该结果为实现高灵敏度液体折射率测量提供了重要理论依据。该传感器结构紧凑,整体长度只有1 200μm,在液体折射率测量领域具有重要的应用价值。